RMO FINAL Flashcards by Ivan Ng

Under certain circumstances is it ok to chain an exit door?

Yes, to keep your building safe from intruders

Yes, to keep students from leaving school
Mel

No, it is never of (FDNY)

Both A and B are correcT

No, it is never of (FDNY)

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How would you calibrate a thermometer?

Place the thermometer in a cup of ice water

Place the thermometer in a cup of hot water

Place the thermometer in superheated steam

Compare temperature to another thermometer

Place the thermometer in a cup of ice water

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What device automatically controls the speed of a steam turbine?

Governor valve

Gimpel valve

Sentinel valve

Main steam valve

Governor Valve

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What happens when a steam turbine reaches critical speed?

Turbine will shut down

Turbine will vibrate violently

Turbine will slow down

Turbine will speed up

Turbine will vibrate violently

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Superheat on the suction line has been increasing gradually for over a week. What could
be the cause?

Leak in the system

System is overcharged

Scale is clogged in the orifice

Leak in the system

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A cold front is coming into the area. What would it cause liquid line solenoid to do?

Close and go off on low pressure

Close and go off on high pressure

Close and go off on low pressure

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What is the sight glass on a compressor used for?

Check refrigerant level

Check oil level

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Shader valve stem caps protect against all except?

Air getting into the system

Refrigerant leaking of the system

Oil leaking out of the system

Damage to the valve

Air getting into the system

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A motor winding is touching the inside of the motor housing. This could result in:

Motor would overheat and shut down

Shock may occur to personnel

Motor would speed up

Motor would slow down

Shock may occur to personnel

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An engineer suspects a short of the motor windings have caused the motor to trip on
overload. The engineer should use what instrument to check the motor:

Capacitor

Voltmeter

Ohmmeter

Ammeter

Ohmmeter

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How many BTU’s are removed in a 30 ton system:

12,000 BTU’s per hour

360,000 BTU’s per minute

12,000 BTU’s per minute

360,000 BTU’s per hour

360,000 BTU’s per minute

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An engineer is requested to replace a gauge on the high side of the system. The pressure
graduation rate should be:

At least 1.2 times the design pressure

Design pressure

A compound gauge

Same as low side pressure

At least 1.2 times the design pressure

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An automatic expansion valve maintains a constant:

Evaporator pressure drop

Evaporator superheat

Refrigerant flow

Evaporator pressure

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If the air louvres below the fans in an induced draft cooling tower become clogged the
rest would be:

A decrease in make up water supply

Higher return water temperature

Lower return water temperature

A lower condenser approach

Higher return water temperature

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You have a cold front and there is a sudden drop in temperature. The thermostat will cause solenoid valve to:

Close and pump the compressor down and shut down on low pressure

Close and the compressor will stop on high pressure

Open and compressor pumps down and goes off on high pressure

Open and compressor will continue to run at a reduced speed

Close and pump the compressor down and shut down on low pressure

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Cross connections and standpipe risers must be painted:

Green

Red

Yellow

Green with yellow stripe

Red

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Ir a sprinkler system is offine for two days how often do you need to inspect it until it is returned back to service?

Only in the morning not at night until restored

Only in the evening not the morning until restored

Continuously 24 hours a day until system is restored

12 hours a day until system is restored

Continuously 24 hours a day until system is restored

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The only refrigerant/temperature chart avallable to a refrigerant engineer lists thg
temperature in degrees Celsius. If the chart indicates a celsius temperature of 5 degrees the
equivalent in Fahrenheit is?

18.4 degrees

39.2 degrees

41 degrees

27 degrees

41 degrees

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In the picture below what does the equipment detect?

Carbon Dioxide

Oxygen

Halogen

Refrigerant leaks

Halogen

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In a building with a multizone standpipe system, how does each zone get supplied with
water?

Each zone will be connected to the main water supply

It will supply only the highest standpipe zone

Each zone will have its own automatic water supply

It will supply only the lowest standpipe zone

Each zone will have its own automatic water supply

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Which service valve should be installed to isolate a dual pressure relief valve while
keeping system in service?

Two way valve

Three way valve

Plug valve

Stop valve

Three Way Valve

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When will the BTU’s exchanged be the greatest?

High evaporator temperature, low condenser temperature

High evaporator temperature, high condenser temperature

Low evaporator temperature, low condenser temperature

Low evaporator temperature, high condenser temperature

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You find that the check valve on a centrifugal pump is leaking. When would the most
damage be caused to the pump?

On shutdown of the pump

On startup of the pump

When another pump is turned on

When servicing the pump

On startup of the pump

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When you are finished leak testing with R22 and nitrogen the next step would be?

Vent refrigerant and nitrogen to open air

Remove refrigerant and nitrogen with recovery tank

Add refrigerant back into system

Add refrigerant if needed and put system back online

Vent refrigerant and nitrogen to open air

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What is the device used to measure the speed of a turbine? Governor Gimpel valve Look Tachometer First stage nozzle gauge

Tachometer

The condenser pump is on the first floor and not running. The pressure gauge shows 55 psi. There is 15 feet for each floor. What floor is the cooling tower on? 10 12 6 8

There is 7.48 gallons per cubic foot. How many gallons of water are in a pipe 8 feet in diameter and 10 feet long? 26 80 3758 748

3758

A technician has been asked to estimate the cost of operating a 5 horse power motor. Because the plant is billed by energy consumed as kilowatt-hours, the technician will have to calculate the conversion. The equivalent in energy of a 5 horse power motor operating for 9 hours in kilowatt-hours is closet to: 33.6 4.79 3.73 11.9

33.6

A circuit breaker has a similar function as what? A fuse A solenoid A resistor A relay

A Fuse

How do you start a centrifugal chiller? Start the chilled water pump, start condenser water pump, start compressor, check oil, start cooling tower Start the chilled water pump, start condenser water pump, check oil, start compressor, start cooling tower Start cooling tower, check oil, start compressor, start the chilled water pump, start condenser water pump Start the chilled water pump, start condenser water pump, check oil, start cooling tower, start compressor

Start the chilled water pump, start condenser water pump, check oil, start cooling tower, start compressor

What does a wiring diagram display? Wiring of components Wiring of switches only Switch functions All of the above

Wiring of components

Filter driers remove? Air and acids Moisture and particles Oil and acids Moisture and air

Moisture and particles

Show a picture of an insulated pump and ask what is this pump? Centrifugal pump Reciprocating pump Centrifugal chill water pump Condenser pump

Centrifugal chill water pump

If 29.92" HG is equal to 14.7 PSIA then 26" HG converts to what in PSIA? 13 12.77 30.3 7.5 d. 7.5

12.77

When charging refrigerant on the low side of a reciprocating machine with manifold gauge what is the position of the manifold? High and low side backseated High and low side frontseated High side backseated low side frontseated High side frontseated low side backseated

High side frontseated low side backseated

You are the engineer running a 2,000 ton steam driven turbine centrifugal refrigeration system supplying chilled water to a college campus with multiple buildings. You are supplying 45 degree chilled water. All the buildings are satisfied except one building. What action should the engine do? Put an additional chilled water pump online Lower the set point from 46 degrees to 40 degrees Add additional make up water to the cooling tower

Put an additional chilled water pump online

The cooling medium for a cooling tower is? Air Water Air and water Tower fan

Air

The charge in a TEV sensing bulb is? Non flammable non toxic similar to refrigerant in system Highly toxic highly flammable Different type of refrigerant than in system

similar to refrigerant in system (FDNY)

What tvpe of sprinkler system needs inspecting? Automatic Non-automatic Residential Commercial, hotel & office buildings

AUTOMATIC

You are performing hot works near a sprinkler head. What can You do to prevent the fire alarm from going off? Take the building offline Drain the sprinkler system in that area Put a non-combustible barrier to protect the sprinkler head Perform hot works in service area

Put a non-combustible barrier to protect the sprinkler head

How long does it take to warm up a steam turbine? 10-15 minutes 30-40 minutes No less than 60 minutes Doesn't need warm-up

10-15 minutes

Why is a pressure relief valve better than a fusible plug? Less costly Minimizes refrigerant loss Can be tested Adjustable

Minimizes refrigerant loss

What is the state of refrigerant entering the compressor on a reciprocating machine? Vapor Superheated vapor Saturated vapor Liquid

Superheated vapor

In the absence of water chemical treatment of a cooling tower? Drain the tower every one to two weeks & replace with fresh water Punch tubes every week Clean condenser pump strainers None of the above

Drain the tower every one to two weeks & replace with fresh water

What is ammonia's refrigerant ASHRAE classification? A1 B3 B2 A3

What is the function of a safety head on a compressor? Capacity control Prevents liquid slugging from damaging the valve plate Purge air from cylinders Prevent friction

Prevents liquid slugging from damaging the valve plate

When is a chemical fire extinguisher system needed? Where water is not sufficient Pre action system Deluge system

Where water is not sufficient

What is most accurate about fire alarm books? Must be kept on premises within 1 year from log of last entry Must be kept in the fire alarm panel Must be kept in the building managers office Must be kept on the premises no less than five years

Must be kept in the fire alarm panel

What is the volume of a box 12"x12"x12" measure? 1728 inches 1728 square inches 1 cubic foot 144 cubic feet

1 cubic foot

A condenser pump is supplied with 85 degree water from a cooling tower and returns to tower at 88 degrees. Engineer is sure the condenser tubes are clean and free of obstructions, condenser has high condenser pressure. The reason for this could be? Overcharge of refrigerant Undercharge of refrigerant Thermostat is damaged Wide open water regulating valve

Overcharge of refrigerant

Fireproof decorations in buildings are useful for? Seasonal purposes Don't catch fire in an emergency Usually energy efficient Help reduce heat load

Don't catch fire in an emergency

What is the lowest temperature a cooling tower can be? Ambient temperature Dry bulb temperature Wet bulb temperature Between dry bulb and wet bulb

Wet bulb temperature

Manifold hoses should be equipped with? Quick disconnects Low loss fittings Schrader valves Service apertures

Low loss fittings

Water regulating valves are used to? Vary flow based on water temperature Maintain refrigerant temperature Maintain condenser pressure to a pre-determined level

Maintain condenser pressure to a pre-determined level

Which of the following does not require flame resistant treatment? Decorations in a hotel lobby Decorations in a building lobby Art work in a museum A heavy curtain in a theater

Art work in a museum

Regardless of the ASHRAE refrigerant classification in use, in the event of a refrigerant escaping the engineer should be aware of? Refrigerant fire Refrigerant toxicity Asphyxiation

Asphyxiation

What type of refrigerant is found inside the machines gauges? R-134A Same type of refrigerant inside the machine R-22 Glycol

Same type of refrigerant inside the machine

If resistance is cut in half, what happens to the power factor? Gets cut by half Increases by a factor of two Decreases by a factor of two Increased by half

Increases by a factor of two

What are pre hot works procedures performed prior to hot works? Check area once a day leading up to hot works Check area one week prior to hot works Check area day of hot works Check area day after hot works

Check area once a day leading up to hot works

A chilled water system has an air cooled condensing unit on a roof during cold weather has what type of protection? Glycol running through it Heater coil Air limiting device Resistor

Air limiting device

What is a compressor safety head? A pressure relief on the low side Cylinder head with a pressure relief on the high side A spring on the valve plate Rupture disc

A spring on the valve plate

Standpipe certificate should be available for? FDNY & OSHA FDNY and building inspector FDNY and EPA FDNY and NFPA

FDNY and building inspector

Which of the following does not require flame resistant treatment? Decorations in a hotel lobby Decorations in a building lobby Art work in a museum A heavy curtain in a theater

Art work in a museum

A FDNY permit is required to conduct hot works for? Brazing Welding Use of oxygen and flammable gas All of the above

Use of oxygen and flammable gas

FDNY is most concerned with which ASHRAE refrigerant classification? A1 B2 A3 B1

How long must a Fire alarm log book be kept? 5 years 1 year from last entry 6 months 3 years

3 YEARS

What is the minimum requirement an engineer needs to log readings? Every 2 hours Once per shift Every hour Every 4 hours

Once per shift

You are the only engineer on duty with a machine running. A vice president tells you to shovel snow. What should you do? Call your union rep Shovel snow Do not leave building Shovel but check the machine regularly

Do not leave building

How often must you do emergency power testing? Weeklv Bi-weekly Annually Monthly

Monthly

What is the responsibility of a B29 COF holder? Maintain the battery system Test the battery system Inspect the battery system Repair minor problems

Inspect the battery system

Why is a refrigerant gauge called a compound gauge? You can read the pressure on the high side and the low side You can read the temperature and pressure It has scales for different types of refrigerant At reads positive pressure and vacuum

At reads positive pressure and vacuum

What is not required to be serviced annually? Fire extinguishers Fire pump motors Compressors Diesel engine systems

Compressors

What is the advantage of a shell and tube condenser, as opposed to a shell and coil condenser? Easier to clean Prevents less leaks Better heat transfer Less efficient

Better heat transfer

Fusible plugs on a condenser? Release refrigerant by pressure The melting point is marked on it Can be back seated Are not allowed by code

The melting point is marked on it

How much extra refrigerant can be stored in a machine room? 20% above the normal charge 220 Ibs The amount equal to the design pressure 330 lb

330 lbs

What is used on an outside pipe to prevent it from freezing? Capacitor Resistor Heater coil Transformer

Resistor

Of the following centrifugal chillers are best characterized as? High tonnage, low pressure machines Low tonnage, high pressure machine High tonnage, high pressure machine Low tonnage, low pressure machine

High tonnage, low pressure machines

As an engineer you notice pressure drops across the evaporator. You check and notice the external equalizer line is disconnected. What will occur in the evaporator? Evaporator will flood Evaporator will starve Evaporator will stabilize Evaporator will be unaffected

Evaporator will flood

When entering Phase Il fireman's service, what statement is correct? Does not need a special key Can only be used by a firefighter The elevator operator is the only person that could control the elevator Must be tested semi-annually

The elevator operator is the only person that could control the elevator

What is the most widely used regulation book by operating engineers is? OSHA EPA BOMA NFPA

EPA

What type of refrigerant do you need FDNY approval for? Ammonia R-22 Propane R-134A

PROPANE

Centrifugal pressure is determined by? Speed of motor Variable guide vanes Design speed Electrical voltage

Speed of motor

A single phase 208 VAC circuit has 2 hot wires the third is the? Spare wire Ground Control wire Common

Ground

Liquid refrigerant that has passed through a metering device is a? High pressure liquid Sub cooled liquid Low pressure saturated liquid Low pressure vapor

Low pressure saturated liquid

With a 75 degree dry bulb and a 73 degree wet bulb the relative humidity is? Normal Very low 100% relative humidity Very high

Very high

After recovering liquid refrigerant from a centrifugal chiller the next step is to? Blow the system out with nitrogen Pull a deep vacuum Recover vapor Leak Test system

Recover vapor

Where is the muffler located? Between the compressor and condenser Between the evaporator and condenser After the condenser Before the compressor

Between the compressor and condenser

In the picture the valve is in what position: The valve is closed The valve position cannot be determined The valve is cracked open The valve is fully opened

The valve is cracked open

A high-side float valve is used to maintain: Constant level of refrigerant in the evaporator Constant rate of refrigerant flow Constant flow of condenser water Constant level of refrigerant in condenser

Constant level of refrigerant in the evaporator

A facility has failed to maintain water treatment to a refrigerant system? Clogging of the cooling tower Increase in the condenser pressure Corrosion of the cooling tower metals Cavitation of condense water pumps

Increase in the condenser pressure

Which of these compressors is not a positive displacement type compressor? Rotary Screw Reciprocating Centrifugal

Centrifugal

Where is emergency power not required according to code? Egress illumination Data centers Fire pumps High rise elevators

Data centers

There is a decrease in the efficiency of a reciprocating compressor. The most likely caused by: High suction pressure Leaking suction valve Low suction pressure Leaking discharge line

Leaking suction valve

The suction and discharge valve of the reciprocating compressor are mounted as follows? Suction and discharge valve on the upper side of the plate Suction and discharge valve below the valve plate Discharge valves below the valve plate and suction valve above it Discharge valve on top of the valve plate and suction valve below

Discharge valve on top of the valve plate and suction valve below

You are the engineer running a 2000 ton (steam-driven turbine) centrifugal refrigeration system, a refrigeration system supplies chilled water to a college campus with multiple buildings. While making your rounds you notice that the discharge pressure of your condenser water pumps is significantly lower than the normal. Which following action would you avoid taking? Put on a additional condenser water pump Flush out the bucket strainer of the condenser water pump Send your assistant to check for cooling tower level Put on an additional surface condenser pump and lower the chilled water set point

Put on an additional surface condenser pump and lower the chilled water set point

A water pump is discharge against head 92 feet of water, this approximately to a pressure of: 95 psi 20 psi 40 psi 180 psi

40psi

Which one of the following will connect to the middle port on a gauge manifold? Solenoid valve King valve Vacuum pump Suction or discharge service valves

Vacuum pump

The most important reason for installing a muffler in reciprocating refrigerant machine is ? Prevent compressor damage Prevent condenser damage To contain the compressor pulsation noise To reduce velocity of the refrigerant

To reduce velocity of the refrigerant

Of the following, the statement that most accurately characterize a hermetic compressor is that it? Typically has a pressure lubrication system Will have only the motor enclosed in a gas tight housing Will have both the compressor and motor enclosed is gas tight housing Is erected in the field

Will have both the compressor and motor enclosed is gas tight housing

The use of oil in the refrigeration machine is to: Mix the oil with liquid refrigerant Add non condensables to refrigerant Reduce wear and friction in the compressor parts None of the above

Reduce wear and friction in the compressor parts

The following is a desirable property in a refrigeration? High corresponding operation pressure High viscosity High latent heat High corresponding compressor discharge temperature

High latent heat

The cooling medium for an evaporative condenser is: Air and water Air Water Condenser fan

Air and water

The ratio of the actual pressure of water vapor in the atmosphere to the saturated pressure give temperature is? Partial pressure Humidly affect Absolute humidity Relative humidity

Partial pressure

The only refrigerant/temperature chart available to a refrigerant engineer list the temperature is degrees Celsius if the chart indicates a Celsius temperature of 4 degrees to equivalent to F? 35.2 degrees 39.2 degrees 27.0 degrees 18.4 degrees

39.2 degrees

A refrigerant engineers was instructed to charge of 60 ton plant with R134A Refrigerant. The refrigerant engineer will most likely find the charging valve on the Discharge side of the compressor Receiver High side pressure side of the system Low pressure side of the system

Low pressure side of the system

A refrigerant engineer verifies that a chilled water pump is cavitating. Of the following the most likely cause for this condition is: A faulty cooling tower water level controller Operating at sustaining high loads Too long a period between pump servicing Water leaks through the mechanical seals

Water leaks through the mechanical seals

Hoy would you put an additional pump online? Open suction valve, open discharge valve gradually Open suction valve, close discharge valve Close suction valve, open discharge valve Open suction valve and slowly close discharge valve

Open suction valve, open discharge valve gradually

Of the following, the major advantage of a shell and coil condenser is: It is easier to clean without disturbing the refrigerant connection There is less dangers of developing leaks Has higher heat transfer coefficient Better level liquid control all the condenser may be activated

There is less dangers of developing leaks

A chill water system uses refrigerant R134 a leak in the evaporator shell may result in? Set off the refrigerant monitor alarm Higher than normal high side pressure The foam of ice around the point of leak Low pressure shut down

Set off the refrigerant monitor alarm

What are steam ejectors used for on the surface condenser of a system with a turbine? To regulate turbine speed To increase the surface area of the condenser To create a proper operating exhaust vacuum To remove steam condensate from the condenser

To create a proper operating exhaust vacuum

Water and moisture is a serious problem in a refrigerant system how to avoid? Use of fins in refrigerant line Proper evacuation at the charging of the system Proper handling of refrigerant and oil to avoid exposure to mixture Use of high viscosity oil in the connection

Proper evacuation at the charging of the system

The most important requirements for a good evaporator is that? Air or liquid refrigerant can be used as required by the medium being cooled It must have enough cooling surface to absorb the required heat Operates only when the heat load exceeds a minimum The refrigerant is contained in tubes

It must have enough cooling surface to absorb the required heat

While on duty a refrigeration engineer notice that the suction line to the compressor and part of the compressor itself is frosted of the following, the most likely reason for this condition would be? Low condenser water temperature The TEV is almost close There is a blockage in the liquid line There is not enough refrigerant in the system

There is not enough refrigerant in the system

While doing a routine line inspection, the engineer notices the bulb of the TXV on the floor refrigerant engineer should attach bulb at the? Three quarters way towards the end of the coil The inlet end of the coil The expansion valve outlet The outlet end of the coil

The outlet end of the coil

Open suction valve, open discharge valve gradually

There is less dangers of developing leaks

A chill water system uses refrigerant R134 a leak in the evaporator shell may result in: Set off the refrigerant monitor alarm Higher than normal high side pressure The foam of ice around the point of leak Low pressure shut down

Set off the refrigerant monitor alarm

What are steam ejectors used for on the surface condenser of a system with a turbine: To regulate turbine speed To increase the surface area of the condenser To create a proper operating exhaust vacuum To remove steam condensate from the condenser

To create a proper operating exhaust vacuum

Water and moisture is a serious problem in a refrigerant system how to avoid: Use of fins in refrigerant line Proper evacuation at the charging of the system Proper handling of refrigerant and oil to avoid exposure to mixture Use of high viscosity oil in the connection

Proper evacuation at the charging of the system

The most important requirements for a good evaporator is that: Air or liquid refrigerant can be used as required by the medium being cooled It must have enough cooling surface to absorb the required heat Operates only when the heat load exceeds a minimum The refrigerant is contained in tubes

It must have enough cooling surface to absorb the required heat

The efficiency of the refrigerant cycle is affected by the operation of the condenser. Of the following, a more efficient centrifugal compressor operation results from: Raising the condenser liquid level to the maximum Lowering the chilled water set point Raising the condenser head pressure Lowering the condensing pressure

Lowering the condensing pressure

The heat removed from the refrigerant in a condenser is: Sensible and latent heat Latent heat only Radiant heat only Sensible heat only

Sensible and latent heat

The refrigerant unit that you have been assigned to is being taken out of service for a major repair. You have been assigned to withdraw refrigerant for storage in suitable containers. According to the NYC fire code, you must ensure that the containers: Do not weigh more than 200 pounds when filled Are approved by the US Department of Transportation Are approved by the OSHA Association Do not exceed 55 Gallon in Capacity

Are approved by the US Department of Transportation

Which of the following best describes how the cylinder unloader work? Keep in the suction valve opened while the compressor is in the return stroke Controls the clearance volume in the compressor with a solenoid Controls the opening of the passage into the compressor with variable vanes Unloads the piston to create less pressure

Keep in the suction valve opened while the compressor is in the return stroke

In most semi Hermetic compressors, the suction vapor is used to: Removes oil from the motor housing Cools the motor Minimizes oil foaming Removes oil foam from the shaft

Cools the motor

The amount of refrigerant that flows through the orifices of a economizer is determined by the: Number of economizer stages Temperature of the high side refrigerant Number of compressor stages Difference between the high side and low side pressure

Difference between the high side and low side pressure

The installation of an inline refrigerant cleaning system is advisable: For high pressure refrigerant systems To purge non-condensables For systems using toxic refrigerant To remove impurities from the system

To remove impurities from the system

The type of refrigerant system that is least likely to leak refrigerant into the building space that are being cooled: The direct vented closed system The direct closed system Any system using reciprocating compressor The indirect system

The indirect system

The suction pressure of a reciprocating compressor is 65 PSG. The discharge pressure of this compressor is 120 PSIG. The atmospheric is 14.7 PSI. The compression ratio for the given condition is closest to: 2.07 4,41 1.69 1.84

1.69

A superheated vapor is a: Dry vapor at the saturation temperature Dry saturated vapor Dry vapor above the saturation temperature Vapor with minimal amount of included liquid

Dry vapor above the saturation temperature

A refrigerant engineer verifies that a condenser water pump is cavitating. Of the following the most likely cause for this condition is: A faulty cooling tower water level controller Operating at sustaining high loads Too long a period between pump servicing Refrigerant leaks through the pumps packing

A faulty cooling tower water level controller

A centrifugal water pump is known as a lift pump when the: The pump lifts the water into the pump upon startup The water supply to the pump suction inlet is below the pump level The discharge head exceed 150 feet The pump is started with the suction valve open

The water supply to the pump suction inlet is below the pump level

A TXV is used to maintain constant: Refrigerant flow Evaporator pressure Evaporator pressure drop Evaporator superheat

Evaporator superheat

The chilled water supply to the building is 55F. If the chiller is being used for human comfort, should you be concerned about this, and why? Yes, this temperature is too low for human comfort purpose Yes, this temperature is too high for human comfort purpose No, 55F is within an acceptable range No, temperature gauges often give false high readings

Yes, this temperature is too high for human comfort purpose

The packing gland of a centrifugal pump serves to: Keep the bearing cooled Keeps air out of the pumps when the impeller housing is under negative pressure The drip part of the packing gland gives evidence that there is water in the pump All of the answers are correct

The drip part of the packing gland gives evidence that there is water in the pump

Capacity control of a reciprocating hermetic compressor is typically achieved through. Regulating the opening of the discharge valve Variation of the condenser water temperature Regulating the opening of the TXV Operation of the hot gas bypass valve

Operation of the hot gas bypass valve

The most important reason to sub-cool the refrigerant in the condenser is to ensure that: A pure liquid refrigerant will enter the metering device Liquid slugs will not enter the compressor The condenser is working efficiently The cooling tower has sufficient water

A pure liquid refrigerant will enter the metering device

A refrigeration engineer is logging reading from a reciprocating system, compressor discharge temperature have dropped significantly and the suction line pressure is high. Which of the following that may be causing this set of conditions Compressor cycle An expansion valve that is open to wide Malfunction of a unloader An expansion valve that is closed to much

An expansion valve that is open to wide

A low side float valve is used to maintain: A constant refrigerant flow The water level in the cooling towers The level of refrigerant in the condenser The level of the refrigerant in the evaporator

The level of the refrigerant in the evaporator

Regarding fire safety, which ASHRAE refrigerant safety classification indicates no flammability and lower toxicity? A3 A1 B1 B2

When an expansion valve is operating properly, at the end of the evaporator will contain: Saturated liquid refrigerant Only liquid refrigerant Only vapor Only superheated vapor

Only superheated vapor

What information is not contained in a Material Safety Data Sheet? Health and physical hazards of the material Safety work practice and required protective equipment of the material Procedures that should be followed in case of an emergency Cost of the material

Cost of the material

23. In a steam turbine, what is the function of the Kingsbury thrust bearing. Maintain axial positioning of the rotor shaft Maintain first stage steam pressure Compensate for coupling misalignment Adjust shaft torque at start up

Maintain axial positioning of the rotor shaft

A centrifugal water pump is considered to be fully primed when. The pump is full of air Liquid or leaking past the packing gland The pump runs with no knocking noise The pump is full of liquid

The pump is full of liquid

Copper tubing refrigerant lines must be installed for a new system. It is a well known service practice that tubing collapses at bends that must be made, the refrigerant engineer should use. Brazed elbows Annealed tubing Never type tubing bender A very small bend radius

Never type tubing bender

A reciprocating compressor is making a knocking sound during operation. If the refrigerant worn parts are not causing the knocking, what is probably the cause. Misalignment of the compressor motor The slugging of the liquid refrigerant Parallel misalignment of the compressor and motor Insufficient lubrication

The slugging of the liquid refrigerant

In order for a refrigerant to become superheated it must be heated in a section of the low side refrigerant line: Where the medium being cooled is hottest Where refrigerant pressure is lowest Where no liquid refrigerant is present

Where no liquid refrigerant is present

All Liquid has been recovered from a system to be overhauled, the system. Should not be opened until all vapor has been recovered Should have air pumped through it and vented to atmosphere before being opened Should be pumped with dry nitrogen before being opened Can be safety opened and repaired

Should not be opened until all vapor has been recovered

29. When a refrigerant engineer uses a portable compressor recovery unit to remove vapor refrigerant form a refrigeration system the removal rate of the refrigerant will gradually slow down because. The vapor density is decreasing The refrigerant temperature is dropping The compressor speed decreasing The compressor efficiency is decreasing

The vapor density is decreasing

You are the engineer running a 2000-ton (steam-driven turbine) centrifugal refrigeration system, a refrigeration system supplies chilled water to a college campus with multiple buildings. During the course of making your rounds, you check the 9 cell cooling tower on the roof. You note the water level in all of the cooling tower cells is very low. Which one of the following immediate action would take? Gradually lower the chiller water set point on the refrigerant system Add additional make up water to cooling tower Create a deeper vacuum pressure in the surface condenser and turn on a second condensate pump Drastically increase the speed of the cooling tower

Add additional make up water to cooling tower

A rooftop water cooling tower is connected to a water pump in the building basement with a 12 inches diameter pipe with the pump turn off, a pressure gauge at the pumps inlet show a pressure of 140 PSIG the height of the water column, in feet, would be closest to? 277 375 323 190

323

What device protects the steam turbine from excessive speed? Governor assembly Maximum speed set point control High steam flow cutout Double seat globe valve

Governor assembly

A refrigeration compressor has failed to turn on. The refrigeration engineer on duty verifies that the electrical circuit to the motor, including all switches and circuit breakers, is complete according to recommended service practice, the next item to be checked would likely be the: Temperature and pressure controls Liquid line solenoid valve Refrigerant charge Cooling tower operation

Temperature and pressure controls

Refrigerants are characterized by their physical properties included flashpoint, refrigeration effect, and others of the refrigerants in commercial and industrial the highest latent heat and refrigerant effect is: R-12 Ammonia R-22 Propane

Ammonia

On what characteristics is ASHRAE refrigerant safety group classification system: Explosives and toxicity Explosives and flammability Flammability and toxicity Acidity and explosiveness

Flammability and toxicity

Of the following, and example of an in-line refrigerant cleaning system that may be used with a centrifugal compressor containing R123 refrigerant is: Refrigerant recycling Refrigerant recovery Refrigerant reclaiming Refrigerant disposal

Refrigerant recycling

Information about the physical and chemical properties of a hazardous material can be found in: NY Medical code Manufacturers Safety Directions Sheet Material Safety Data Sheet NYC Fire Code

Material Safety Data Sheet

What is the function of the turbine auxiliary oil pump? Check proper oil level in pump before start up Stand by pump if main pump fails Recovers oil from the condensate tank Establish oil pressure during turbine start up

Establish oil pressure during turbine start up

The rupture disc for a low-pressure centrifugal refrigeration machine is normally located on the: Compressor suction Condenser Compressor discharge TXV

Compressor suction

What is the primary reason ribbed metal piping is used for electrical wires connected to the refrigeration system shown below? It is easier to install than non-ribbed metal piping It allows the flexibility and accounts for vibrations It allows for ventilating the heat from wires It is less costly to use than non-ribbed metal piping

It allows the flexibility and accounts for vibrations

41. Modern compressors usually seal the rotating shaft as it exits the compressor housing a spring loaded seal made of . Rubber Low friction plastic Metal or carbon Graphite loaded fiber

Metal or carbon

The British Thermal Unit (BTU) is the measurement of heat of energy. If 10 BTU are transferred to 10 pounds of water, the water temperature increase will be closest to: 10F 1C 1F 10C

A reciprocating compressor cylinder has a 10 inches bore and 14 inches stroke. The volume of refrigerant, in cubic inches, will be closer to: 1808 1406 1099 1002

1099

An electrically operated control requires 24 volts to operate to change the available 110 volts to 24 volts. Rectifier Step-down capacitor Low temperature wire Transformer

Transformer

In an indirect refrigeration system, of the following, the one that would not be used as a cooling medium for the building spaces being cooled is: A calcium chloride solution A sodium chloride solution R22 refrigerant Glycol

R22 refrigerant

On a steam turbine, what would cause the atmospheric valve to open? Low vacuum in the surface condenser Leaking tubes in the surface condenser All answers are correct Dirty tubes in the surface condenser

All answers are correct

You are the engineer running a 2000-ton (steam-driven turbine) centrifugal refrigeration system a refrigeration system supplies chilled water to a college campus with multiple buildings making your rounds, you notice that condenser water pump #1 is making a lot of noise, the discharger gauge reading of the condenser water pump is fluctuating drastically, and motor of the condenser pump #1 is running very hot. Which of the following actions would you take: Turn on pump #2, shut off pump #1, and trouble shot pump #1 Gradually increase the chilled water set point from 40F to 46F, so the machine can cool down Leave pump #1 running, but immediately put in a call to the service contractor

Turn on pump #2, shut off pump #1, and trouble shot pump #1

Electric devices may be used to provide built in defrosting of refrigeration machine evaporator units. These devises are classified as. Induction coils Thermostats Capacitors Resistors

Resistors

The flash point of compressor lubrication oil: Should be higher than the compression temperature Is the temperature at which the oil start to foam Is the temperature at which the viscosity is measured Should be lower than the compression temperature

Should be higher than the compression temperature

The primary way of achieving capacity control of a centrifugal compressor is by: Variation in steam pressure Adjustment of the impeller inlet pre-rotation vanes Operation of the hot gas bypass valve Adjustment of the thermal expansion valve

Adjustment of the impeller inlet pre-rotation vanes

Cooling tower water requires the addition of chemical additives in order to: Lower head pressure Regulate and maintain the PH level Reduce the formation of scale and algae Comply with EPA regulation

Reduce the formation of scale and algae

The viscosity of lubrication oil is described by a number. A low viscosity number describes oil that: Flows easily Should not be used with refrigerant Flows poorly Does not provide good lubrication

Flows easily

The most likely reason for a refrigeration engineer to use a psychrometer is to measure Atmosphere pressure Relative humidity level of the atmosphere Temperature of the atmosphere Undesired substance in the atmosphere

Relative humidity level of the atmosphere

The most important reason to use at least two compressors in a cascade system is to: Accomplish higher temperature Avoid very high compression ratio for each compressor Avoid the need for water-cooled condenser Divide the cooling load between the compressors

Avoid very high compression ratio for each compressor

56. The suction service valve of a reciprocating compressor is front seated and the compressor run until the low pressure cut-out shut the compressor off. When the machine is stopped, the refrigeration engineer notices that the suction pressure increase rapidly. The most probably cause this pressure rise: A faulty gauge A leaking suction service valve All answers are correct Malfunction of a compressor valve

Malfunction of a compressor valve

Regarding the functioning of a steam turbine, why is it advisable to keep moisture in the inlet low as possible? Decrease vacuum leaks Decrease turbine warm up time Keeps turbine blades wear to minimum Keeps steam traps from rusting

Keeps turbine blades wear to minimum

According to the attached Material Safety Data Sheet R134 is a? Dark blue liquid Clear, odorless liquid and vapor Yellow gas that smells like rotten eggs Light blue liquid

Clear, odorless liquid and vapor

Under normal condition, the refrigerant enters the compressor as a: Low pressure vapor and leaves as a high pressure saturated vapor Low pressure superheated vapor and leaves as a high pressure vapor Low pressure superheated vapor and leaves as a high pressure saturated liquid High temperature vapor and leaves as a low pressure vapor

Low pressure superheated vapor and leaves as a high pressure vapor

While operating an R-22 single acting compressor system, the refrigeration engineer noticed oil foaming in the crankcase. This condition most likely, would have been caused by a: Sudden drop in the crankcase pressure High oil temperature Moisture in the oil Addition of liquid Freon

Sudden drop in the crankcase pressure

Assume that an engineer is able to observe refrigerant water and oil together. The fluids would settle in the container from top to bottom: Water, oil, refrigerant Oil, refrigerant, water Refrigerant, oil, water Oil, water, refrigerant

Oil, water, refrigerant

What is the function of the vacuum breaker in a steam turbine. To achieve a faster coast down cycle To keep main bearing oil from foaming To keep vacuum at proper level To indicate presence of vacuum leak

To achieve a faster coast down cycle

An equalizer line on a TXV is used to: Eliminate the pressure across the evaporator Compensate for the pressure drop across the evaporator coil Equalize the pressure across the TXV diaphragm or below Correct for pressure drop in the thermal bulb capillary lines

Compensate for the pressure drop across the evaporator coil

If R134 accidentally touches a refrigerant engineer's skin, what first aid should be applied from the MSDS? R134 is a low acute toxicity, no special medical attention is required Promptly flush skin with water until all chemical is removed Rub the frozen parts The frostbite parts in hot water (above 130F) to warm them up

Promptly flush skin with water until all chemical is removed

In a multi stage centrifugal compressor, each stage: Has higher tip speed than one before it Handles more refrigerant than the one before it Is identical in volume to the other stages Has smaller volume than the one before it

Is identical in volume to the other stages

A refrigeration engineer notices excessive cycling of the temperature control for a reciprocating compressor refrigeration unit. The crankcase temperature is high, the compressor discharge temperature low, the suction line temperature is high of the following the one that may causing this set of condition. An expansion valve that is open too wide The purge unit operation The condenser operation, dirty tubes or cooling control Faulty compressor valves

Faulty compressor valves

On an operating centrifugal compressor refrigerant unit, the refrigeration engineer notices the compressor is short cycling. The unit is using low side float valve as a meeting device of the following requirements this would indicate that: Inspection should be made for a dirty and partially plugged discharge line The system is undercharged with refrigerant The compressor wiring be inspected The system is overcharged with refrigerant

The system is undercharged with refrigerant

The vessel depicted below may be used in connection with. Refrigerant recovery Refrigerant recycling Refrigerant reclaiming Refrigerant disposal

Refrigerant recovery

A refrigeration system used jet ejector to raise settled oil mixed with refrigerant to the oil pump if a restriction in the refrigerant flow to the jet ejector develops: The flow of oil will be unaffected The temperature of the refrigerating exiting the jet will decrease The oil will not lift if it is mixed with less refrigerant There may be insufficient head to lift the oil

There may be insufficient head to lift the oil

70. An indirect low temperature refrigerant system frequently uses glycol, instead of salt brine as the intermediate cooling medium. An advantage of this choice is: The elimination of corrosion High flow rate Better thermal conduction Low cost

The elimination of corrosion

In relation to the suction pressure of a compressor, the reading on the oil pressure gauge should read in the range closer to: 15 to 30 PSI higher 15 to 30 PSI lower 30 to 60 PSI lower 60 to 80 PSI higher

15 to 30 PSI higher

Non-condensable gases like air, oil vapor, or nitrogen travel through a refrigerant system with the refrigerant they usually accumulate in the: Condenser Compressor crankcase Filter drier Evaporator

Condenser

The advantage of forced draft cooling tower over natural draft cooling towers is: Smaller tower size That it uses less water That it improves power efficiency in water tower Reduced energy cost

Smaller tower size

The sole refrigeration engineer on duty in a building is permitted to leave the building refrigeration system when it is in operation only when: Lunch or dinner occur System is an automatic operation Relieved by another licensed refrigeration engineer The assistant provides coverage or supervision

Relieved by another licensed refrigeration engineer

A system controlled by a TXV show high discharge pressure and high normal sub-cooling. The cause is most probably a: Superheat settings that has been set incorrectly Refrigerant overcharge Leaking compressor discharge valve Low system amperage draw

Refrigerant overcharge

Which of the following is a correct statement? 2.5 gallon of water weight 10.7 pounds 2.5 gallon of water weight 1.05 pounds 2.5 gallons of water weighs 20.8 pounds 2.5 gallons of water 2.5 cubic feet

2.5 gallons of water weighs 20.8 pounds

Liquid level gauge glasses (except the bulls eye) are generally equipped with: Manual and automatic closing shut off valves Manual shut-off valves only Automatic shut-off valves only Either manual or automatic closing shut-off valves

Automatic shut-off valves only

Copper and aluminum are frequently used for condenser tubes in refrigeration system, these metals are used because of there: Easy availability High heat transfer coefficient Resistance to corrosion Resistance to failing

High heat transfer coefficient

Assume that a refrigeration engineer has a choice of four valves to select from. Which of the following is the most effective type of valve to control pressure? Ball valve Quarter turn valve Gate valve Plug valve

Plug valve

Where must the Material Safety Data Sheets be located? Near the entrance to the machine room Where flammable liquids are used Where available to all employees

Where available to all employees

RMO FINAL Flashcards

(199 cards)